runtime/trace, internal/trace: script to collect canned traces

This adds support to the runtime/trace test for saving traces
collected by its tests to disk and a script in internal/trace that
uses this to collect canned traces for the trace test suite. This can
be used to add to the test suite when we introduce a new trace format
version.

Change-Id: Id9ac1ff312235bf02f982fdfff8a827f54035758
Reviewed-on: https://go-review.googlesource.com/32290
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>

diff --git a/src/internal/trace/mkcanned.bash b/src/internal/trace/mkcanned.bash
new file mode 100755 (executable)
index 0000000..78c5572
--- /dev/null
+++ b/src/internal/trace/mkcanned.bash
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+# Copyright 2016 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+# mkcanned.bash creates canned traces for the trace test suite using
+# the current Go version.
+
+set -e
+
+if [ $# != 1 ]; then
+    echo "usage: $0 <label>" >&2
+    exit 1
+fi
+
+go test -run ClientServerParallel4 -trace "testdata/http_$1_good" net/http
+go test -run 'TraceStress$|TraceStressStartStop$' runtime/trace -savetraces
+mv ../../runtime/trace/TestTraceStress.trace "testdata/stress_$1_good"
+mv ../../runtime/trace/TestTraceStressStartStop.trace "testdata/stress_start_stop_$1_good"

diff --git a/src/internal/trace/parser.go b/src/internal/trace/parser.go
index 40176237495b0c17bca8860ab78a8d9153df9bad..efa85409a21f7e24214e153be027069bdf01a695 100644 (file)
--- a/src/internal/trace/parser.go
+++ b/src/internal/trace/parser.go
@@ -128,6 +128,8 @@ func readTrace(r io.Reader) (ver int, events []rawEvent, strings map[uint64]stri
        }
        switch ver {
        case 1005, 1007, 1008:
+               // Note: When adding a new version, add canned traces
+               // from the old version to the test suite using mkcanned.bash.
                break
        default:
                err = fmt.Errorf("unsupported trace file version %v.%v (update Go toolchain) %v", ver/1000, ver%1000, ver)

diff --git a/src/runtime/trace/trace_test.go b/src/runtime/trace/trace_test.go
index 5fad3fb7f048336b8b3ccf551f8e254c18b2ecb9..191bdd939acc4ef704ae7a1d0b96d125f7903f34 100644 (file)
--- a/src/runtime/trace/trace_test.go
+++ b/src/runtime/trace/trace_test.go
@@ -6,8 +6,10 @@ package trace_test
 
 import (
        "bytes"
+       "flag"
        "internal/trace"
        "io"
+       "io/ioutil"
        "net"
        "os"
        "runtime"
@@ -17,6 +19,10 @@ import (
        "time"
 )
 
+var (
+       saveTraces = flag.Bool("savetraces", false, "save traces collected by tests")
+)
+
 func TestTraceStartStop(t *testing.T) {
        buf := new(bytes.Buffer)
        if err := Start(buf); err != nil {
@@ -31,6 +37,7 @@ func TestTraceStartStop(t *testing.T) {
        if size != buf.Len() {
                t.Fatalf("trace writes after stop: %v -> %v", size, buf.Len())
        }
+       saveTrace(t, buf, "TestTraceStartStop")
 }
 
 func TestTraceDoubleStart(t *testing.T) {
@@ -52,6 +59,7 @@ func TestTrace(t *testing.T) {
                t.Fatalf("failed to start tracing: %v", err)
        }
        Stop()
+       saveTrace(t, buf, "TestTrace")
        _, err := trace.Parse(buf, "")
        if err == trace.ErrTimeOrder {
                t.Skipf("skipping trace: %v", err)
@@ -233,6 +241,7 @@ func TestTraceStress(t *testing.T) {
        runtime.GOMAXPROCS(procs)
 
        Stop()
+       saveTrace(t, buf, "TestTraceStress")
        trace := buf.Bytes()
        parseTrace(t, buf)
        testBrokenTimestamps(t, trace)
@@ -376,6 +385,7 @@ func TestTraceStressStartStop(t *testing.T) {
                }
                time.Sleep(time.Millisecond)
                Stop()
+               saveTrace(t, buf, "TestTraceStressStartStop")
                trace := buf.Bytes()
                parseTrace(t, buf)
                testBrokenTimestamps(t, trace)
@@ -436,6 +446,7 @@ func TestTraceFutileWakeup(t *testing.T) {
        done.Wait()
 
        Stop()
+       saveTrace(t, buf, "TestTraceFutileWakeup")
        events, _ := parseTrace(t, buf)
        // Check that (1) trace does not contain EvFutileWakeup events and
        // (2) there are no consecutive EvGoBlock/EvGCStart/EvGoBlock events
@@ -464,3 +475,12 @@ func TestTraceFutileWakeup(t *testing.T) {
                }
        }
 }
+
+func saveTrace(t *testing.T, buf *bytes.Buffer, name string) {
+       if !*saveTraces {
+               return
+       }
+       if err := ioutil.WriteFile(name+".trace", buf.Bytes(), 0600); err != nil {
+               t.Errorf("failed to write trace file: %s", err)
+       }
+}